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Upgrading Your Shells to Beacons

It’s an issue we all encounter, we’re operating in a shell and want to upgrade it to something better. For many, this may be Meterpreter which is absolutely a valid choice. Another option I want to explore in this post is upgrading your shell to a Cobalt Strike Beacon.

In this instance, I’m going to cheat by generating a shell callback with Veil-Evasion to simulate operating in a shell and executing it on a VM.

Now that I have my shell, it’s time to look into upgrading this to something better! First, I’ll need to setup a Beacon listener within Cobalt Strike. This is pretty simple, just select the headphones icon on the top menu and you’ll be presented with the Listener tab. Just select the “Add” button at the bottom and configure your listener as you see fit.

Once you’ve created your listener, it’s time to prep for the shell upgrade. I prefer to use Cobalt Strike’s powershell web-delivery feature to upgrade my shell. To set this up, click the powershell icon on the top menu and configure the attack. In this case, I customized the uri to be “upgrade”, I am using the default port 80, and the listener that I want to utilize was pre-selected.

Now, just select launch, and you’ll be given the command that you can run on your victim machine.

All you need to do now is just copy and paste this command into your shell, and you should see your beacon calling back!

If you have any questions, be sure to let me know! Hop in #Veil on Freenode or hit me up on twitter @ChrisTruncer.